Research Update

Hear Daniel Glaser describe this graphic, which
summarizes the study's results. His caption is available in audio or
text.

Research Update

Daniel Glaser's Latest Study With Ballet and Capoeira Dancers

If you're skilled at a physical activity like ballet, the part of your brain
that controls movement activates differently than the same part in the brain of
someone who's not skilled in that activity. That's what researchers at the
University of College London (UCL) have found in a fascinating new study. The
study has implications for helping injured athletes continue to train without
moving a muscle, and perhaps even helping stroke victims regain lost
movement.

In the UCL study, dancers from London's Royal Ballet and experts in capoeira, a
Brazilian martial arts form, were asked to watch short videos of either ballet
or capoeira dancers performing brief dance moves. While watching the videos,
the dancers were lying perfectly still in an MRI scanner. A control group of
non-dancers also participated in the study, which was published in the December
2004 online edition of Cerebral Cortex.

The researchers found that areas of the brain collectively known as the "mirror
neuron system" showed more activity when a dancer saw movements he had been
trained perform than when he observed movements he hadn't been trained to
perform. (All the dancers in the study were male.) The mirror system in the
non-dancers showed appreciably less activity while watching the videos than
either of the dancers' mirror systems, and the response it had was the same
whether it was watching ballet or capoeira.

Earlier studies with monkeys revealed that brain cells called mirror neurons
respond both when we do something, like pick up an object, and when we simply
watch someone else do it. It was known that these neurons fire when we perform
an action, but it came as a surprise that the same cells also fired when we
only saw that action being performed. The new study went a step further by
showing that such a system operates differently depending on what you are
physically expert at doing.

"This is the first proof that your personal motor repertoire, the things that
you yourself have learned to do, changes the way that your brain responds when
you see movement," says Daniel Glaser, a neuroscientist who was part of the UCL
team. (Hear Glaser discuss the study's results shown in the graph at
left.)

"Our findings suggest that once the brain has learned a skill, it may simulate
the skill without even moving, through simple observation," says UCL's Patrick
Haggard. "An injured dancer might be able to maintain his skill despite being
temporarily unable to move, simply by watching others dance." Similarly, by
understanding how the mirror neuron system works, doctors may be able to better
rehabilitate people whose motor skills were damaged by stroke.—Peter
Tyson

Dr. Glaser's collaborators on the dancer study included UCL's Beatriz
Calvo-Merino, Julie Grezes, Patrick Haggard, and Dick Passingham. For more
about the study, listen to our audio interview with Daniel Glaser in
RealAudio or Windows Media, or
download it (1.2MB MP3) for later listening. (You can also read a transcript of the
interview.) For more on Glaser himself, see his Web site at
www.icn.ucl.ac.uk/dglaser/.